July 2019
Volume 60, Issue 9
Open Access
ARVO Annual Meeting Abstract  |   July 2019
Assessing the ocular refraction from a series of through-focus, double-pass aerial images
Author Affiliations & Notes
  • Pau Santos
    CD6-UPC, Barcelona, Spain
    Visiometrics, Cerdanyola del Vallès, Spain
  • Ricard Tort
    Visiometrics, Cerdanyola del Vallès, Spain
  • Harilaos Ginis
    Department of Research, Athens Eye Hospital, Athens, Greece
  • Raúl Cuevas
    Visiometrics, Cerdanyola del Vallès, Spain
  • Alex Pennos
    Visiometrics, Cerdanyola del Vallès, Spain
  • Footnotes
    Commercial Relationships   Pau Santos, Visiometrics (E); Ricard Tort, Visiometrics (E); Harilaos Ginis, Visiometrics (C); Raúl Cuevas, Visiometrics (E); Alex Pennos, Visiometrics (E)
  • Footnotes
    Support  None
Investigative Ophthalmology & Visual Science July 2019, Vol.60, 4838. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Pau Santos, Ricard Tort, Harilaos Ginis, Raúl Cuevas, Alex Pennos; Assessing the ocular refraction from a series of through-focus, double-pass aerial images. Invest. Ophthalmol. Vis. Sci. 2019;60(9):4838.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : To assess objective refraction by means of Through Focus-Double Pass (TF-DP) images.

Methods : 11 non-cycloplegic and non-dilated healthy eyes from 6 volunteers (aged between 24 to 45 years) were measured in a clinical site (Institut de Microcirurgia Ocular, Barcelona, Spain). Two consecutive measurements of TF-DP for each of the participant’s eye were performed, the first of them by limiting the pupil diameter at 2mm and the second at 5mm by means of a motorized diaphragm optically conjugated with the pupil plane (the larger the pupil, the higher impact of the High Order Aberrations on the DP images). Objective refraction was also measured using a commercial autorefractor (AR) as a reference (KR8900, Topcon, Japan). Their objective refraction was assessed from the energy distribution of each TF-DP image.
The TF-DP technique was first validated with an artificial eye and cylindrical trial lenses to simulate different refractions (cylinder from 0 to 3D in 0.5D increments).
Refractions in conventional script (sphere, cylinder and axis) were converted into power vectors coordinates (M, J0 and J45).

Results : Results from artificial eye and cylindrical trial lenses, demonstrate the ability of the TF-DP to assess the refraction. We found strong correlation between the lens optical power and measured refraction, r=0.97 for 2mm exit pupil and r=0.99 for 5mm exit pupil.
Mean ± Standard deviation (SD) (in Diopters, D) results were M=-1±1.11, J0=-0.18±0.33, J45=0.04±0.27 for AR, M=-0.72±1.36, J0=-0.29±0.57, J45=-0.05±0.40 for 2mm TH-DP and M=-0.93±1.25, J0=-0.14±0.53, J45=0.05±0.32 for 5mm TH-DP.
We found a strong correlation between AR and 2mm TH-DP in terms of M (r=0.89), J0 (r=0.82) and J45 (r=0.87); a strong correlation between AR and 5mm TH-DP in terms of M (r=0.82) and J0 (r=0.89) and moderate correlation between AR and 5mm TH-DP in terms of J45 (r=0.67).
Bland-Altman analysis (Mean Difference±1.96SD (D)) comparing AR and 2mm TH-DP was 0.28±0.94, -0.11±0.61 and -0.09±0.36 and between AR and 5mm TH-DP was 0.01±1.07, 0.00±0.52 and 0.00±0.38 in terms of M, J0 and J45 respectively.

Conclusions : These preliminary results demonstrate that the refractions obtained by TF-DP with 2 and 5mm pupil are in agreement with the ones obtained by the commercial AR. Future work will focus on validating the TF-DP in a larger population and compare it with subjective refraction.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×